Darpa says there are other biological examples of quantum effects — including an explanation, perhaps, for how birds are able to navigate along the Earth’s magnetic fields. The key may be the so-called "quantum Zeno effect," explains thePhysics ArXiv Blog.

One well-known example is that it is possible to slow down the rate at which molecules convert from ortho to para isomers when they are constantly involved in collisions.

[Iannis Kominis at the
University of Crete] says a similar thing happens in birds: the presence of a geomagnetic field extends the lifetime of the singlet-triplet mixture from which the ions recombine. This gives the magnetic field time to bias the outcome of the recombination.